1. Technical Field
The present invention relates to an image forming apparatus and an image forming method wherein a deflecting mirror surface makes a light beam from a light source scan over an effective image region of a latent image carrier and a latent image is formed in this effective image region.
2. Related Art
In a conventional apparatus, a deflecting mirror surface of a resonant scanner deflects a light beam emitted from a light source, the light beam scans over a latent image carrier such as a photosensitive drum, and a line latent image is formed. In the image forming apparatus described in JP-A-2003-25629 for instance, a semiconductor laser is used as a light source and the semiconductor laser emits a light beam whose optical intensity corresponds to an image signal. After deflected by the deflecting mirror surface of the resonant scanner, the light beam thus optically modulated is guided onto a photosensitive drum and scans over the surface of the photosensitive drum. As a result, a latent image corresponding to the image signal is formed on the photosensitive drum.
Further, a beam detector formed by light receiving diodes is disposed next to the photosensitive drum and detects an area near the end of the light beam scanning region. A horizontal synchronizing signal generator circuit generates a horizontal synchronizing signal based on an output from the beam detector, and modulation of the light beam is controlled in synchronization to the horizontal synchronizing signal. This adjusts a write start position at which writing of a line latent image starts.